A collapsible cart assembly for storing and transporting a plurality of objects on a jobsite includes a box for containing objects on a jobsite. A plurality of wheels is each rotatably coupled to the box to roll along a support surface. A plurality of shelving units is provided and each of the shelving units is telescopically coupled to the box. Each of the shelving units selectively support objects for storage and for transportation. Moreover, each of the shelving units is positionable in a deployed position having the shelving units being distributed upwardly from the box and being spaced apart from each other. Each of the shelving units is positionable in a collapsed position having the shelving units being stacked on the box.